Process of producing carbonitrids.



S. PEACOCK. PROCESS OF PRODUCING CARBONITRIDS.

APPLICATION FILED FEB. 14, I912.

Patented Apr. 27, 1915.

wa mer.

UNITED s'rarns .ra'rnur enrich.

SAMUEL PEACOCK, OF CHICAGO, ILLINOIS, POWDER C01VIPANY,- OF WILMINGTON,

JERSEY.

' it appertains to make and use the same.

Ihis invention relates to a process for producing a composition of matter, which I believe to be a carbo-nitrid containing a metal chemically combined with carbon and nitro gen, and has for its objectto chemically fix nitrogen in a manner more proposed. I 1

I may useoxids of almost any of the metals, but I prefer the oxidsof aluminum or of silicon, or of the alkali-earth metals to mix with the carbon and nitrogen; and as an example of the process I will employ for convenience, the oxid of calcium in disclosingthe invention. The exact structural formula new compound is not at present known to me, but I believe its general formula, when calcium is employed, approximates Ca C,N and I believe. it to be a double nitrid of calcium and carbon as expressed by-the forwhich is a carbo-nit'rid compound analogous to the well known double sulfids, an example of which is found in chalcopyrite all as will be more'fully disclosed hereinafter.

the invention consists in the novel steps constituting my process as well as the new carbo-nitrid compound itself, all as will more fully appear hereinafter, and be particularly pointed out'in the claims.

Referring to the accompanying drawings forming a part of this specification in which the figure is a diagrammatic view of one form of furnace suitable for carrying out my invention :-1 indicates any suitable supply for the mixed carbon and lime, 2 valves Specification of Letters Patent.

of the invention, such as expeditious and at a less cost-than those methods heretofore of my With the above andother objects in view,-

the equilibrium ASSIGNOR TO E. I. DU FONT DE NEMOURS DELAWARE, A CORPORATION OF NEW PROCESS OF PRODUCING CARBONITRIDS PatentedApr. 27,1915.

Application filed February 14, 1912." Serial naewnea.

controlling the same, 3 a furnace provided with a refractory lining 4, 5 a resistor of graphite or othersuitable material, 6 a secondresistor, 7 supports for said resistor, 8 rings on the outside ofthe furnace connected with said supports 7 and adapted to make contact with the brushes 9,10,11and 12 included in suitable electric circuits not shown. I

The furnace .is supported by any suitable means as for example, the rollers 14, and is revolved as by the means 15.

16 represents an air-tight connection between the receptacle 1 and the larger. end of the furnace, while 17 represents a similar connection between the exit 18 and the smaller end of the furnace.

The shape of the furnace is preferably conical with its lower side horizontal, and when rotated it therefore carries the material 20 in small particles upwardly on its inner side, and drops the same down at a point nearer the smaller end than it was before. In this way, the material is continuously fed through and evenly heated in the furnace as it rotates.

In order to allow for the expansion and contraction of. the resistors, I preferably provide spring supports 22 which may be suitably made of carbon or other refractory conducting substance.

28 represents a suction pipe' for the pump 24, which communicates with the interior of the connection 16 as shown, and v25 represents a suitable vacuum gage, which is provided with contacts, not shown, connecting with the wires 26.

27 represents any suitable electro-I'nagnetic device adapted to be operated from the gage 25-and of the pump, although my process may be carried out at atmospheric pressure, or even above if desired, so long as the partial pressures of the gaseous products of the reaction do not exceed 760 mm. of mercury.

Since the above apparatus forms no part of my, present invention, I do not deem it necessary to disclose more of its details, and only refer to it here in order to make clearer the process now to be described. Briefly stated, this process consists in taking advantage of the relation which exists between I temperature and pressure a-. ."the formation of the calcium carbonitrid,

controlling the exit valve 28.

' neighborhood of l400 to 1600 centigrade,

while the partial pressure of the gaseous products of the reactionin the-furnace is below that of the atmosphere.

. I In carrying out my process, I remove any gaseous oxygen that may exist in "the fur- .na'ce and take finely divided and dry calcium oxid CaO, and finely. divided dry carbon,

, preferably coke or-charcoal, in the ratio of E56 parts byweigh't of the former to 24 parts .ifzof the latter, thoroughly mixjhe same, and iege. the mixture into the furnace as illus- "ted. I I find in practice-that the process iswfacilitated if an excess of carbon some itimes'ias high as 25 or per cent. is used,

isinceit prevents the formationof calcium 'nitrids Ca N WhlCll contain a much lower percentage of nitrogen than do the carbo-.

' 1n1trids of my process. Said excess-of caris Iin'the furnace, I, preferably subject it under the. conditions above mentioned, by-

.so I

ofwthe carbo-nitrid 1 and'the material fed the electrode 6, less total heatunits are re-;

boir? '-.also insures themore nearly complete conversion of the calcium to the carbo-nitrid form, said excess. of carbon not being 1n ur1- ous to the process.

--"After the mixed calcium oxid and carbon meansof the resistor 5to a temperature of about- 1500-? 0., which effects the formation -a'ccordance with the following equatio I H j. motto grace a,G N +3OO *"As thecar jo-nitrid, however, is formed by theiiulfnace under quired to keep up the. reaction, temperature, becausethe reaction lessens in; velocity .and less heat is absorbed. Therefore, I preferablyinclude the resistor 6 inan independs ent circuit, and pass only suflicientirurrent therethrough to supply the necessary heat in the furnace to correspond with the selected pressure of gas that is being -maintained.

The material is next cooled and discharged from the furnace by .any suitable means.

" g 'liberated from the charge,

Any carbon monoxid G0 which may be the formation of calcium nitrid, 'Ga N to" take place, only two atoms of nitrogen would be fixed to three atoms of calcium.

The above carbo-nitrid compound I do not believe is a cyano-nitrid,or a cyanamid, for cyanogen, ON, cannot be derived from it .will be forced forward by the nitrogen, as well as 'sucked 'The temperatures required for'the reaction will vary with-the metal oxid used; for calcium. oxid it will be about 1500 (3., as above stated; .for aluminum oxid it will be about 1700? 0.; for silicon oxid about 1800 (1., and for magnesium oxid about .'1600 C.

extent as wouldinterfere withthe reaction.

' These temperatures in each case will also varyflwith the'partial pressures of the gaseous products of the reaction in the furnace. I prefer to prevent in all cases, the said partial pressures of the products ofthe reactions,'from rising above 300 of mercury, althoughof course, I may operate the process at any partial pressure that is substantially less than 760 mm. of mercury.

The reaction velocity, as well as the tern-- per-ature of reaction, of course, diminishes with the partial pressure of the products of the reaction, and Ifind .if'I use a partial v pressureof say 250mm, 350'mm., or500 'mm., the reaction is. satisfactory,

An ultimate analysis "shows my carbonitrid- Ca N fi N to. resemble calcium cyanamid, but to be very diflerent in structure, since itdoes not, contain the cyanogen .radical ON. Itcanalso be 'produced with out the intermediary of calcium carbid CaC since said carbid could not be formed under the conditions and temperatures which produce my carbo-nitrid.

I find that in boilingwater or acids my carbo-nitrid' is decomposed into ammonia mto. ammonium and Inpther words,

' pears to be a double nitrid, formed under conditions imposingv no abnormal valencies, for taken separately the nitride exhibit the normal valencies thus:

As stated above, the oxids of aluminum and of silicon, may be substituted in the above disclosure for the oxid of calcium. In other Words, instead of employing 3GaO'in y compound clearly ap-.

I c e (G8N4) s- And, by employing 3SiO instead of 3CaO in said reaction, I may produce a silicon carbo-nitrid Si- N .'(G' N Of course the oxids of other metals may be similarly substituted for the calcium oxid with correspondingly difierent carbo-nitrids.

In all cases the products have similar propertiesand fail to produce cyanogen CN,

' except upon a breaking up of the compound. 15

It is evident that those skilled in the art may vary the above. process without departing from the spirit of my invention,-and therefore, I do not wish to be limited to this disclosure except as may be required by the claims. V

What I claim is 1. The process of producing a carbonitrid, which consists in heating in the presence of nitrogen an oxid of an element having metallic properties with sufficient carbon and to a temperature sufiicient to'produce saidcarbo-nitrid, while preventing the partial pressures of the gaseous products of the reaction from rising sufficiently to interfere with the reaction,-subs tantially as described.

2, The process of producing a carbomtrid, which consists in heating an oxid of an element having metallic properties in the presence of nitrogen with sufiicient carbon and to a temperature sufiicient to produce said carbo-nitrid, while maintaining the par- 'tial pressures of the gaseous products of, the

reaction below 500 millimeters of mercury,

substantially as described. 7 v

3. The process of producing a carbo-v nitrid, which consists in heating an oxid of an element having metallic pro I erties in the presence of nitrogen with su cient carbon and to a temperature sufiicient to produce said carbo-nitrid, while maintaining the partial pressure of the gaseous products of the reaction below 350 millimeters of mercury,

substantially as described.

4. The herein described composition of matter consisting of a carbo-nitrid' containing a metal chemically combined with carbon and nitrogen, but failing to evolve cyanogen (ON) except upon fusion,

stantialIy as described.

In testimony whereof, I afix my signature, in presence of two witnesses.

SAMUEL PEACOCK.

Witnesses A. S. COUTURIER,

J. F. FEN IG.

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